On the replicability of physiological responses

Science is often claimed to be amid a reproducibility crisis, as evidenced by low replicability of many classic findings across multiple fields. Yet it is not clear how widespread this purported problem is. Physiological responses have the potential for replicability issues because of laboratory-specific biases in animal maintenance as well as technically complex methodologies that are often undertaken using bespoke combinations of equipment. Here, we took advantage of a cross-laboratory manipulative study on metabolic rate to assess the replicability of food restriction effects on metabolic scaling and level. Across seven skink species from the Egernia species complex and two universities, we found these responses to be extremely replicable. The slope of the interspecific metabolic scaling relationship was near one and animals reduced their mass-independent rates of energy use by an average of 32% in response to food restriction. This response was consistent across universities. Our study highlights that well designed and replicated studies with a large effect size can indeed be replicable and showcases the value of designing studies that allow tests of replicability to be incorporated explicitly. Such studies will be particularly valuable for treatment effects that generate a small effect size.